In the petroleum industry, the petrochemical industry, and in the chemical industry in general, liquid products are transported from containers of various types to other containers via hoses and loading arms. Such liquids may include oil, gasoline, acids, alkaline solutions, asphalt, herbicides, and so on. These liquids may be highly flammable or corrosive, and may also be liquids or semi-liquids (highly viscous liquids). The containers that receive the liquid fuel and chemical products may be stationary such as holding tanks, or mobile such as tanker trucks and rail cars. Generally, most of the transferring operations consist of transferring liquid oils, fuels and chemical products from a refinery to a tanker truck, or similar, and then from the tanker truck to an outlet--such as a gasoline station in the case of petroleum products. For the purposes of discussion, the petroleum industry will generally be referred to. The technology is applicable, however, to virtually any chemical industry.
The loaders that are used are usually permanently attached to a platform and piped from storage tanks. The fuels and chemicals are then pumped from the storage tanks to the vessels transporting the products for further distribution. There is an elongated metal spout or hose on the free end of each loader for interfacing with the container that is receiving the liquid products.
More specifically, a loading arm delivering product from a holding tank at a refinery has a spout on the end thereof, with the spout being adapted for insertion into a co-operating receiving portion on a tanker truck. When not in use, the spout remains elevated and oriented such that the opening of the spout is downwardly directed. The spout is placed into the co-operating receiving portion and a handle or the like on the spout is activated. Activation of this handle opens a co-operating valve that controls the release of liquid fuels, oils and chemical products through the spout. The liquid petroleum products are released into the tanker truck. In order to stop the transfer of liquid petroleum products through the spout the handle is deactivated, usually by releasing it, and the co-operating valve closes.
There is one problem, however, in that a small amount of the liquid petroleum product remains in the spout below the level of the valve, after the valve is closed. This small amount of liquid petroleum product generally remains on the inner surfaces of the spout by adhesion or surface tension; and because the spout is oriented such that the opening in the spout is downwardly directed the small amount of the liquid petroleum product drips out of the spout over a period of time. Obviously, either this dripping liquid petroleum product ends up either on whatever is directly underneath, whether it be the ground, asphalt, cement, gravel, or whatever. If the surface is not asphalt, cement, or similar, the petroleum product would seep into the water table. In order to preclude the petroleum product from reach the ground area, it must be captured in some sort of container.
Such a container must be highly resistant to liquid petroleum products, it must be sturdy enough to withstand a rugged environment--both in terms of weather and rough physical use--and it also must clamp tightly onto a spout such that it does not fall off the spout and preferably such that it does not move significantly while on the spout. It has been found that such movement of a drip cup on a spout can be undesirably noisy and also can cause damage to the spout. Preferably, a drip cup would attach to the end of a spout in a snug and secure manner such that undue movement between the two is precluded.